Blister packaging is widely used in the packaging industry. Within the health care field, blister packaging is the most rapidly growing method of packaging medication. A limiting factor to the effectiveness of many medications is patient compliance with the prescription. Medications usually must be taken at specific intervals based on their pharmacokinetics to maximize plasma levels, and deviation from the prescribed interval, or failure to take a dose, may result in ineffectiveness or adverse effects. Patient non-compliance with prescribed medication increases with the patient's age.
It is widely acknowledged that it would be useful to prescribing physicians and pharmacists to have a record of their patients' compliance with medication regimens. This information could then be used to educate patients. It could also prevent unnecessary and expensive changes in medication because of a lack of clinical response due to poor compliance.
In addition, there is increasing concern about the possibility of tampering with packaged pharmaceuticals.
There are also environmental factors that can decrease the effectiveness of some medications.
Inventions have been described to address the issue of patient compliance with blister-packaged medication. For example, Wilson and Petersen Canadian Patent Application No. 2353350 of Jul. 20, 2001 describes an invention designed to monitor the use of blister packaged medication. That invention relies on a system of electrically-conducting traces communicating with an Integrated Circuit (IC). Expelling the content from its blister breaks the trace, and the time and other characteristics of the event are recorded in the IC's memory. These data can later be retrieved and utilized.
Wilson and Petersen Canadian Patent Application No. 2366887 of Dec. 31, 2001 describes the application of a similar device to the lidstock prior to it being incorporated into a blister package via a form-fill-seal machine. This is a further refinement of the previous invention, but still relies on electrically-conducting traces passing in proximity to the blisters, the breaking of which trigger the recording of the events in the IC's memory for later retrieval.
The methods described in these patent applications involve systems of electrically-conducting traces located in such a way to be broken when the contents of each blister are expelled. One limitation of these methods is the complexity of arranging a system of traces, one for each blister, to arrive without crossing at the IC. Since there are many possible arrangements for the blisters on a blister package (different numbers and sizes of the contents), the prior art requires individualized design and tooling for each blister package configuration. Another disadvantage of the prior art is the difficulty of connecting the electrically-conducting traces to the pins of the IC. There is also the problem of ensuring that the traces are not broken by means other than expelling the contents, such as scratching or bending the blister package.
Given these limitations it is therefore desirable to provide a packaging device that is easy to use and capable of monitoring the use of package contents, and which does not require individual electrically-conducting traces for each blister to improve reliability and facilitate the manufacturing process. It is further desirable that such device be universally applicable or, at least, require a minimum of individualized design and tooling. It is also desirable that such device be compatible with blister packaging technology currently in widespread use.